Internal driving fixture



Jan. 31, 1933. J. E. LOVELY INTERNAL DRIVING FIXTURE Filed April 8, 1930 Patented Jan. 31, 1933 umreo srAr-es JOHN E. LOVELY, or SPRINGFIELD, VERMONT, As'sIGNoIt so 'i ofi Ei S a LAiIiso'NfiA- CHINE COMPANY, or SPRINGFIELD, vERiib 'r, A companion or witness INTERNAL DRIVING i fiiiifirti Application filed April 8,

This invention relates to work driving means for lathes and the like by which the work is rotated with a spindle and has for an object to provide such a device which on gages the work inside of a bore therein, thus leaving the external surface free for machining operations. To this end the fixture has a hub portion over which the work is placed,

this hub portion having an eccentrically pivoted jaw which in normal driving direction of the fixture automatically wedges against the inner face of the work and so holds the work against rotation relative to the hub H portion of the fixture. The fixture may also 15 be provided with means for correctly locating the work prior to its driving engagement.

For a more complete understanding of this invention, reference may be had to the accompanying drawing in which Figure 1 is a central longitudinal section through the fixture and Work and certain parts of the work spindle.

Figure 2 is a section on line 2-2 of Fig- 25 ure 1. V

Figure 3 is an end elevation of the fixture. As shown in the drawing the fixture comprises a body member 1 having a hub portion 2. At one end this hubportion is provided 130 with a portion of larger diameter as at 3 having a shoulder portion 4 which serves as an abutment against which the work 5 may be placed. This work 5, as shown, is provided with a central opening 6 which provides a 35 surface for engagement by the driving fixture so that substantially the entire external surface of the work is free for machining operations. The body portion 1 is provided at one end with an extension 61, which as shown best in Figure 3, is provided with a squared portion 7 outwardlyof which it has a portion of cylindrical contour 8 terminating in a conical bevel 9. This bevel portion 9 is formed to engage a mating flared face 10 of a spindle 11 which has fixed; thereto a nose member 12 having a central projecting boss 13 provided with a tapering external face 14. A face plate 15 having a mating tapered socket fits over the tapered portion 13 and may be fixed to the face plate as by means shoulder 4 and also to hold the-taperedpor 101- seiiai Na-Maser.

of bolts such as This plate: pro

vided: with a transverse groove-'17 3 within which ride ribs '18. on? the inner face :of a

driving plate '19 which hasflfa' squaredihole to receivethe squared portion 7 ofjthe fix J- ture' and this as thespiridl'e rotates to trans mit driving'rotatfionto the fixture' Theplate 19 may be fixed to the plate l5 asiiby wbolts, 311Gb as 20: i i 'a The opposite end portion of the'body: is provided with a central extensiori on which is slidably mounted a-work retaining iiiem v ber 26. This member is formed substantial- 1y ,eiip shaped, beingprovfided with-an an nulanflange 27 at its large end which abuts a face of the work 5 and holds itagainst the shoulder portion 4." The" member 2621s shown i is soniewhat longer than theextensioh 25 and is provided'with-a closed end 28 havingla central socket opening 29 to receive-the. point .of a lathe center 30 which will commonly be the center of thelath e tailstock. 1 Presa sure of the 'tailstock eenter on this member 26f acts to hold the work firmly against the tion 9 of the fixture the spindle. f V p a a V. v V The hub portion 2, a s shown besti'n Figure 2; is provided with a't recess withinwhich is piyotally mounteda work-"engaging jaw 36.- The pivotal mounting of thisjaw-is ecw against the seat10' of centric to' the axis of the body member so that-by rocking this jaw on its fulcrum its outer end may be caused to approach orrecede from the inner face ofthelbiore of the work. It is normally held con'tiuuoitislyv pressed outwardly against the Workas'by' means ofaplug' '37 seated inasocket 38 and pressed outwardly against the'jaw 36 asby means of'a spring 39: 1;

The means forfulcruming the jaw 36' are best shown in Figure 1-; e Referring to this I figurefit will be sTeen-tliat'opp'osite'endsofthe, jaw 36 are provided with alined conical de-' pression lOand 4L1. Thebodypo'rtion .is pro-- videdat one side ofthe'recess 35' with a sock et portion 42 within whichi's positiorieda ball i seated against a spring''. This ball is adapted to engage in: thedepression 4110f the jaw and actsKa-s alatch to holdthe jaw N 61 and 80f the" body. Slidable'within this opening is a'rod 50 having a conical innerflend 51' engageable in the depression 40. This rod 50 is adjustable from a'nd to engagement with gaging in said opening and adjustable to en gage in the other of said depressions, and means for holding said member in such position.

depressions, a fulcrum member slidably e'ne I In testimony whereof have afiixed my 7 signature v i V a 1 E. LOVELY.

the jaw and when in engagement "therewith acts toholdthe jaw within therhub socket and also actsas a fulcrum mernbr'therefor co I operating with the ball 42 with which it isin axial'alinement The other'end portion of I r the opening 8lis shown'as threaded as at 52 to. receive'anexternally threaded plug 53,

their-inner endy'of whi'ch bears' against the,

' outerrend of the-rod 50=and holds itfrom re- 'tracting 'outIof conta ct with the jaw 36. This Q fplug 53 maybe held in adjusted position as" by nieaiis'of a setscrew. 54 threadedthrough anopenfing15'5- extending radially within the portion 8;. The jaw member 36 is so,;positioned that. in the normal direction of rota tion: of the fixture, as shown by the arrow at f I Figure-2, its. outer end-tends to wedge against the jinne'rface of. the work, thus clamping the work'onqtheihub portion. ,By a

I afterithe member 26 has been removed m'ent' rele'asably securing saidjaw in said Fr-orn' the-foregoing description of an embodiment vofthis invention, it'should be evident to those skilledin the art that various slight rocking motiongiven to'the work in the saniefl direction when the-spindlefis sta v, 'tionary,zthe'work is freed from the bodypor tion and jaw'and may-belreadily withdrawn changes and .modifications'might be'made l without departing from the spirit or scope c f 'ofthisiinven'tion as defined by theiappended claimsq Iclaim:

1:.A ,fixturecomprising a body having 9,

;- portion oi'rer which work maybe placed,'saidv body hayinga recess, awork engaging jaw invsaid recess, aspri'ng pressed fulcrum 'ele-' recess with {capability of limited pivotal A her in position; 55

movement about. an. axis eccentric to said body-'sport-ion' into and out of engagement with work on said portion, a fulcrum memher 'engageable with; said jaw opposite to i said element, and means for fixing said mern- V 'portion-over'which work may be placed, said portion haylng a recess and an openingex- Qtendingfrom one end portion of-said body eccentric to its axis and communicating'with 1 SaldlGCB SS-Mld having a socket 1n the oppo-' "site wall-of said recess in alinement withsaid L open ng, a-work engaging jaw in saidrecess,

said f aw havlng oppositely disposed depressions, a spring'press'ed fulcrum element seat-' ed a n'said socket and engagingv'in one of said 2, A fixture .cornprisingabody havinga v I 

